The invention relates to a novel photobioreactor for producing biomass.
Photobioreactors are fermenters in which phototrophic microorganisms, such as algae, cyanobacteria and purple bacteria are cultivated, that is to say in which either the growth and the propagation of these cells is made possible or the production of various substances is promoted by means of phototrophic cells.
Such photobioreactors are described, for example, in the following publications:
(i) xe2x80x9cBiomass and Icosapentaenoic Acid Productivities from an Outdoor Batch Culture of Phaeodactylum tricornutum UTEX 640 in an Airlift Tubular Photobioreactorxe2x80x9d, Appl. Microbiol. Biotechnol. (1995), 42, pp. 658-663,
(ii) xe2x80x9cAutotrophic Growth and Carotenoid Production of Haematococcus pluvialis in a 30 Liter Air-Lift Photobioreactorxe2x80x9d, Journal of Fermentation and Bioengineering (1996), Vol. 82, No. 2, pp. 113--118,
(iii) xe2x80x9cLight Energy Supply in Plate-Type and Light Diffusing Optical Fiber Bioreactorsxe2x80x9d, Journal of Applied Phycology (1995), 7, pp. 145-149,
(iv) xe2x80x9cA Simplified Monodimensional Approach for Modeling Coupling between Radiant Light Transfer and Growth Kinetics in Photobioreactorsxe2x80x9d, Chemical Engineering Science (1995), Vol. 50, No. 9, pp. 1489-1500.
A principle field of application of photobioreactors is the production of microalgae, which have a share of 30% of the primary production of biomass generated worldwide. In this connection, they are the most important CO2 consumers. Microalgae are therefore capable of having an environmental load reduction effect if they are used for regenerative substance production. Substances that are produced in this way then contribute to the reduction of CO2 emission into the atmosphere since they replace fossil-produced substances.
The microalgae include, on the one hand, the procaryotic cyanobacteria as well as eucaryotic microscopic algae classes. These organisms supply a wide variety of substance classes that can be used for pharmaceutical, cosmetic, nutritional and animal nutrition purposes and for technical purposes (for example, heavy-metal adsorption). Important substance classes in this connection are lipophilic compounds, such as, for example, fatty acids, lipids, sterols and carotenoids, hydrophilic substances such as polysaccharides, proteins or amino acids and phycobilin proteins (pigments), and also the total biomass as protein-rich raw material low in nucleic acid.